package com.gaosai.staff.view;

import java.util.ArrayList;
import java.util.List;

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;

/**
 * 自定义流式布局 如显示标签了等等组件 
 * @author willis
 */
public class CustomFlowLayout extends ViewGroup {

	/***
	 * 构造方法时调用 
	 * @param context  上下文 
	 */
	public CustomFlowLayout(Context context){
		this(context, null);
	}
	
	/**
	 * 从xml加载的时候默认会调用这个方法
	 * @param context
	 * @param attrs
	 */
	public CustomFlowLayout(Context context, AttributeSet attrs){
		this(context, attrs, 0);
	}
	
	/***
	 * 如果设置了style一些属性时调用这个方法
	 * @param context
	 * @param attrs
	 * @param defStyle
	 */
	public CustomFlowLayout(Context context, AttributeSet attrs, int defStyle){
		super(context, attrs, defStyle);
	}


	
	/**
	 * 测量子view的大小 最后再算自己的大小 
	 * Description:TODO
	 * @param widthMeasureSpec
	 * @param heightMeasureSpec
	 */
	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec){
		
		//取得模式和大小
		int sizeWidth = MeasureSpec.getSize(widthMeasureSpec);
		int modeWidth = MeasureSpec.getMode(widthMeasureSpec);
		int sizeHeight = MeasureSpec.getSize(heightMeasureSpec);
		int modeHeight = MeasureSpec.getMode(heightMeasureSpec);

		// wrap_content
		int width = 0;
		int height = 0;

		// 记录每一行的宽度与高度
		int lineWidth = 0;
		int lineHeight = 0;

		// 得到内部元素的个数
		int cCount = getChildCount();

		for (int i = 0; i < cCount; i++){
			View child = getChildAt(i);
			// 测量子View的宽和高
			measureChild(child, widthMeasureSpec, heightMeasureSpec);
			// 得到LayoutParams
			MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams();

			// 子View占据的宽度
			int childWidth = child.getMeasuredWidth() + lp.leftMargin+ lp.rightMargin;
			// 子View占据的高度
			int childHeight = child.getMeasuredHeight() + lp.topMargin+ lp.bottomMargin;

			// 换行
			if (lineWidth + childWidth > sizeWidth - getPaddingLeft() - getPaddingRight()){
				// 对比得到最大的宽度
				width = Math.max(width, lineWidth);
				// 重置lineWidth
				lineWidth = childWidth;
				// 记录行高
				height += lineHeight;
				lineHeight = childHeight;
			} else{// 未换行
				// 叠加行宽
				lineWidth += childWidth;
				// 得到当前行最大的高度
				lineHeight = Math.max(lineHeight, childHeight);
			}
			// 最后一个控件
			if (i == cCount - 1){
				width = Math.max(lineWidth, width);
				height += lineHeight;
			}
		}

		//Log.e("TAG", "sizeWidth = " + sizeWidth);
		//Log.e("TAG", "sizeHeight = " + sizeHeight);

		setMeasuredDimension(
				//设置子view测量的值 如果不是EXACTLY那么就是warp_content样式的。
				modeWidth == MeasureSpec.EXACTLY ? sizeWidth : width + getPaddingLeft() + getPaddingRight(),
				modeHeight == MeasureSpec.EXACTLY ? sizeHeight : height + getPaddingTop()+ getPaddingBottom()//
		);

	}

	/**
	 * 存储所有的View
	 */
	private List<List<View>> mAllViews = new ArrayList<List<View>>();
	/**
	 * 每一行的高度
	 */
	private List<Integer> mLineHeight = new ArrayList<Integer>();

	@Override
	protected void onLayout(boolean changed, int l, int t, int r, int b)
	{
		mAllViews.clear();
		mLineHeight.clear();

		// 当前ViewGroup的宽度
		int width = getWidth();

		int lineWidth = 0;
		int lineHeight = 0;

		List<View> lineViews = new ArrayList<View>();

		int cCount = getChildCount();

		for (int i = 0; i < cCount; i++)
		{
			View child = getChildAt(i);
			MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams();

			int childWidth = child.getMeasuredWidth();
			int childHeight = child.getMeasuredHeight();

			// 如果需要换行
			if (childWidth + lineWidth + lp.leftMargin + lp.rightMargin > width - getPaddingLeft() - getPaddingRight()){
				// 记录LineHeight
				mLineHeight.add(lineHeight);
				// 记录当前行的Views
				mAllViews.add(lineViews);

				// 重置我们的行宽和行高
				lineWidth = 0;
				lineHeight = childHeight + lp.topMargin + lp.bottomMargin;
				// 重置我们的View集合
				lineViews = new ArrayList<View>();
			}
			lineWidth += childWidth + lp.leftMargin + lp.rightMargin;
			lineHeight = Math.max(lineHeight, childHeight + lp.topMargin + lp.bottomMargin);
			lineViews.add(child);

		}// for end
			// 处理最后一行
		mLineHeight.add(lineHeight);
		mAllViews.add(lineViews);

		// 设置子View的位置

		int left = getPaddingLeft();
		int top = getPaddingTop();

		// 行数
		int lineNum = mAllViews.size();

		for (int i = 0; i < lineNum; i++){
			// 当前行的所有的View
			lineViews = mAllViews.get(i);
			lineHeight = mLineHeight.get(i);

			for (int j = 0; j < lineViews.size(); j++){
				View child = lineViews.get(j);
				// 判断child的状态
				if (child.getVisibility() == View.GONE){
					continue;
				}

				MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams();

				int lc = left + lp.leftMargin;
				int tc = top + lp.topMargin;
				int rc = lc + child.getMeasuredWidth();
				int bc = tc + child.getMeasuredHeight();

				// 为子View进行布局
				child.layout(lc, tc, rc, bc);

				left += child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin;
			}
			left = getPaddingLeft() ; 
			top += lineHeight ; 
		}

	}

	/**
	 * 与当前ViewGroup对应的LayoutParams
	 */
	@Override
	public LayoutParams generateLayoutParams(AttributeSet attrs){
		return new MarginLayoutParams(getContext(), attrs);
	}

}
